/*
 * FLAC (Free Lossless Audio Codec) decoder
 * Copyright (c) 2003 Alex Beregszaszi
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

/**
 * @file flac.c
 * FLAC (Free Lossless Audio Codec) decoder
 * @author Alex Beregszaszi
 *
 * For more information on the FLAC format, visit:
 *  http://flac.sourceforge.net/
 *
 * This decoder can be used in 1 of 2 ways: Either raw FLAC data can be fed
 * through, starting from the initial 'fLaC' signature; or by passing the
 * 34-byte streaminfo structure through avctx->extradata[_size] followed
 * by data starting with the 0xFFF8 marker.
 */

#include <inttypes.h>
#include <stdbool.h>
#include "bitstream.h"
#include "golomb.h"

#include "decoder.h"

/*** optimised for use with cortex-m ***/
#define CPU_ARM

#if defined(CPU_COLDFIRE)
#include "coldfire.h"
#elif defined(CPU_ARM)
#include "arm.h"
#endif

#define FFMAX(a,b) ((a) > (b) ? (a) : (b))
#define FFMIN(a,b) ((a) > (b) ? (b) : (a))

static const int sample_rate_table[] ICONST_ATTR =
{	0, 0, 0, 0,
	8000, 16000, 22050, 24000, 32000, 44100, 48000, 96000,
	0, 0, 0, 0
};

static const int sample_size_table[] ICONST_ATTR =
{ 0, 8, 12, 0, 16, 20, 24, 0 };

static const int blocksize_table[] ICONST_ATTR = {
	0,    192, 576 << 0, 576 << 1, 576 << 2, 576 << 3,      0,      0,
	               256 << 0, 256 << 1, 256 << 2, 256 << 3, 256 << 4, 256 << 5, 256 << 6, 256 << 7
};

static const uint8_t table_crc8[256] ICONST_ATTR = {
	0x00, 0x07, 0x0e, 0x09, 0x1c, 0x1b, 0x12, 0x15,
	0x38, 0x3f, 0x36, 0x31, 0x24, 0x23, 0x2a, 0x2d,
	0x70, 0x77, 0x7e, 0x79, 0x6c, 0x6b, 0x62, 0x65,
	0x48, 0x4f, 0x46, 0x41, 0x54, 0x53, 0x5a, 0x5d,
	0xe0, 0xe7, 0xee, 0xe9, 0xfc, 0xfb, 0xf2, 0xf5,
	0xd8, 0xdf, 0xd6, 0xd1, 0xc4, 0xc3, 0xca, 0xcd,
	0x90, 0x97, 0x9e, 0x99, 0x8c, 0x8b, 0x82, 0x85,
	0xa8, 0xaf, 0xa6, 0xa1, 0xb4, 0xb3, 0xba, 0xbd,
	0xc7, 0xc0, 0xc9, 0xce, 0xdb, 0xdc, 0xd5, 0xd2,
	0xff, 0xf8, 0xf1, 0xf6, 0xe3, 0xe4, 0xed, 0xea,
	0xb7, 0xb0, 0xb9, 0xbe, 0xab, 0xac, 0xa5, 0xa2,
	0x8f, 0x88, 0x81, 0x86, 0x93, 0x94, 0x9d, 0x9a,
	0x27, 0x20, 0x29, 0x2e, 0x3b, 0x3c, 0x35, 0x32,
	0x1f, 0x18, 0x11, 0x16, 0x03, 0x04, 0x0d, 0x0a,
	0x57, 0x50, 0x59, 0x5e, 0x4b, 0x4c, 0x45, 0x42,
	0x6f, 0x68, 0x61, 0x66, 0x73, 0x74, 0x7d, 0x7a,
	0x89, 0x8e, 0x87, 0x80, 0x95, 0x92, 0x9b, 0x9c,
	0xb1, 0xb6, 0xbf, 0xb8, 0xad, 0xaa, 0xa3, 0xa4,
	0xf9, 0xfe, 0xf7, 0xf0, 0xe5, 0xe2, 0xeb, 0xec,
	0xc1, 0xc6, 0xcf, 0xc8, 0xdd, 0xda, 0xd3, 0xd4,
	0x69, 0x6e, 0x67, 0x60, 0x75, 0x72, 0x7b, 0x7c,
	0x51, 0x56, 0x5f, 0x58, 0x4d, 0x4a, 0x43, 0x44,
	0x19, 0x1e, 0x17, 0x10, 0x05, 0x02, 0x0b, 0x0c,
	0x21, 0x26, 0x2f, 0x28, 0x3d, 0x3a, 0x33, 0x34,
	0x4e, 0x49, 0x40, 0x47, 0x52, 0x55, 0x5c, 0x5b,
	0x76, 0x71, 0x78, 0x7f, 0x6a, 0x6d, 0x64, 0x63,
	0x3e, 0x39, 0x30, 0x37, 0x22, 0x25, 0x2c, 0x2b,
	0x06, 0x01, 0x08, 0x0f, 0x1a, 0x1d, 0x14, 0x13,
	0xae, 0xa9, 0xa0, 0xa7, 0xb2, 0xb5, 0xbc, 0xbb,
	0x96, 0x91, 0x98, 0x9f, 0x8a, 0x8d, 0x84, 0x83,
	0xde, 0xd9, 0xd0, 0xd7, 0xc2, 0xc5, 0xcc, 0xcb,
	0xe6, 0xe1, 0xe8, 0xef, 0xfa, 0xfd, 0xf4, 0xf3
};

static int64_t get_utf8(GetBitContext *gb) ICODE_ATTR_FLAC;
static int64_t get_utf8(GetBitContext *gb)
{
	uint64_t val;
	int ones = 0, bytes;

	while(get_bits1(gb))
		ones++;

	if     (ones == 0) bytes = 0;
	else if(ones == 1) return -1;
	else               bytes = ones - 1;

	val = get_bits(gb, 7 - ones);
	while(bytes--) {
		const int tmp = get_bits(gb, 8);

		if((tmp >> 6) != 2)
			return -2;
		val <<= 6;
		val |= tmp & 0x3F;
	}
	return val;
}

static int get_crc8(const uint8_t *buf, int count) ICODE_ATTR_FLAC;
static int get_crc8(const uint8_t *buf, int count)
{
	int crc = 0;
	int i;

	for(i = 0; i < count; i++) {
		crc = table_crc8[crc ^ buf[i]];
	}

	return crc;
}

static int decode_residuals(FLACContext *s, int32_t* decoded, int pred_order) ICODE_ATTR_FLAC;
static int decode_residuals(FLACContext *s, int32_t* decoded, int pred_order)
{
	int i, tmp, partition, method_type, rice_order;
	int sample = 0, samples;

	method_type = get_bits(&s->gb, 2);
	if (method_type > 1) {
		//fprintf(stderr,"illegal residual coding method %d\n", method_type);
		return -3;
	}

	rice_order = get_bits(&s->gb, 4);

	samples = s->blocksize >> rice_order;

	sample =
	    i = pred_order;
	for (partition = 0; partition < (1 << rice_order); partition++)
	{
		tmp = get_bits(&s->gb, method_type == 0 ? 4 : 5);
		if (tmp == (method_type == 0 ? 15 : 31))
		{
			//fprintf(stderr,"fixed len partition\n");
			tmp = get_bits(&s->gb, 5);
			for (; i < samples; i++, sample++)
				decoded[sample] = get_sbits(&s->gb, tmp);
		}
		else
		{
			for (; i < samples; i++, sample++) {
				decoded[sample] = get_sr_golomb_flac(&s->gb, tmp, INT_MAX, 0);
			}
		}
		i = 0;
	}

	return 0;
}

static int decode_subframe_fixed(FLACContext *s, int32_t* decoded, int pred_order) ICODE_ATTR_FLAC;
static int decode_subframe_fixed(FLACContext *s, int32_t* decoded, int pred_order)
{
	const int blocksize = s->blocksize;
	int a, b, c, d, i;

	// printf("decode_subframe_fixed  pred_order : %d\r\n", pred_order);
	/* warm up samples */
	for (i = 0; i < pred_order; i++)
	{
		decoded[i] = get_sbits(&s->gb, s->curr_bps);
	}

	if (decode_residuals(s, decoded, pred_order) < 0)
		return -4;

	/***
	a = decoded[pred_order - 1];
	b = a - decoded[pred_order - 2];
	c = b - decoded[pred_order - 2] + decoded[pred_order - 3];
	d = c - decoded[pred_order - 2] + 2 * decoded[pred_order - 3] - decoded[pred_order - 4];
	***/

	switch(pred_order)
	{
	case 0:
		break;
	
	case 1:
		a = decoded[pred_order - 1];
	
		for (i = pred_order; i < blocksize; i++)
			decoded[i] = a += decoded[i];
		break;
	
	case 2:
		a = decoded[pred_order - 1];
		b = a - decoded[pred_order - 2];
	
		for (i = pred_order; i < blocksize; i++)
			decoded[i] = a += b += decoded[i];
		break;
	
	case 3:
		a = decoded[pred_order - 1];
		b = a - decoded[pred_order - 2];
		c = b - decoded[pred_order - 2] + decoded[pred_order - 3];
	
		for (i = pred_order; i < blocksize; i++)
			decoded[i] = a += b += c += decoded[i];
		break;
	
	case 4:
		a = decoded[pred_order - 1];
		b = a - decoded[pred_order - 2];
		c = b - decoded[pred_order - 2] + decoded[pred_order - 3];
		d = c - decoded[pred_order - 2] + 2 * decoded[pred_order - 3] - decoded[pred_order - 4];
	
		for (i = pred_order; i < blocksize; i++)
			decoded[i] = a += b += c += d += decoded[i];
		break;
	
	default:
		return -5;
	}

	return 0;
}

static int decode_subframe_lpc(FLACContext *s, int32_t* decoded, int pred_order) ICODE_ATTR_FLAC;
static int decode_subframe_lpc(FLACContext *s, int32_t* decoded, int pred_order)
{
	int sum, i, j;
	int64_t wsum;
	int coeff_prec, qlevel;
	int coeffs[pred_order];

	/* warm up samples */
	for (i = 0; i < pred_order; i++)
	{
		decoded[i] = get_sbits(&s->gb, s->curr_bps);
	}

	coeff_prec = get_bits(&s->gb, 4) + 1;
	if (coeff_prec == 16)
	{
		//fprintf(stderr,"invalid coeff precision\n");
		return -6;
	}
	qlevel = get_sbits(&s->gb, 5);
	if (qlevel < 0)
	{
		//fprintf(stderr,"qlevel %d not supported, maybe buggy stream\n", qlevel);
		return -7;
	}

	for (i = 0; i < pred_order; i++)
	{
		coeffs[i] = get_sbits(&s->gb, coeff_prec);
	}

	if (decode_residuals(s, decoded, pred_order) < 0)
		return -8;

	if ((s->bps + coeff_prec + av_log2(pred_order)) <= 32) {

		(void)sum;
		lpc_decode_arm(s->blocksize - pred_order, qlevel, pred_order, decoded + pred_order, coeffs);

	} else {

		for (i = pred_order; i < s->blocksize; i++)
		{
			wsum = 0;
			for (j = 0; j < pred_order; j++)
				wsum += (int64_t)coeffs[j] * (int64_t)decoded[i - j - 1];
			decoded[i] += wsum >> qlevel;
		}

	}

	return 0;
}

// __attribute__ ((section ("RAMCODE")))
static inline int decode_subframe(FLACContext *s, int channel, int32_t* decoded)
{
	int type, wasted = 0;
	int i, tmp;

	s->curr_bps = s->bps;
	if(channel == 0) {
		if(s->decorrelation == RIGHT_SIDE)
			s->curr_bps++;
	} else {
		if(s->decorrelation == LEFT_SIDE || s->decorrelation == MID_SIDE)
			s->curr_bps++;
	}

	if (get_bits1(&s->gb))
	{
		//fprintf(stderr,"invalid subframe padding\n");
		return -9;
	}
	type = get_bits(&s->gb, 6);
//    wasted = get_bits1(&s->gb);

//    if (wasted)
//    {
//        while (!get_bits1(&s->gb))
//            wasted++;
//        if (wasted)
//            wasted++;
//        s->curr_bps -= wasted;
//    }
#if 0
	wasted = 16 - av_log2(show_bits(&s->gb, 17));
	skip_bits(&s->gb, wasted + 1);
	s->curr_bps -= wasted;
#else
	if (get_bits1(&s->gb))
	{
		wasted = 1;
		while (!get_bits1(&s->gb))
			wasted++;
		s->curr_bps -= wasted;
		//fprintf(stderr,"%d wasted bits\n", wasted);
	}
#endif
//FIXME use av_log2 for types
	if (type == 0)
	{
		//fprintf(stderr,"coding type: constant\n");
		tmp = get_sbits(&s->gb, s->curr_bps);
		for (i = 0; i < s->blocksize; i++)
			decoded[i] = tmp;
	}
	else if (type == 1)
	{
		//fprintf(stderr,"coding type: verbatim\n");
		for (i = 0; i < s->blocksize; i++)
			decoded[i] = get_sbits(&s->gb, s->curr_bps);
	}
	else if ((type >= 8) && (type <= 12))
	{
		//fprintf(stderr,"coding type: fixed\n");
		if (decode_subframe_fixed(s, decoded, type & ~0x8) < 0)
			return -10;
	}
	else if (type >= 32)
	{
		//fprintf(stderr,"coding type: lpc\n");
		if (decode_subframe_lpc(s, decoded, (type & ~0x20) + 1) < 0)
			return -11;
	}
	else
	{
		//fprintf(stderr,"Unknown coding type: %d\n",type);
		return -12;
	}

	if (wasted)
	{
		int i;
		for (i = 0; i < s->blocksize; i++)
			decoded[i] <<= wasted;
	}

	return 0;
}

// __attribute__ ((section ("RAMCODE")))
static int decode_frame(FLACContext *s) ICODE_ATTR_FLAC;
static int decode_frame(FLACContext *s)
{
	int blocksize_code, sample_rate_code, sample_size_code, assignment, crc8;
	int decorrelation, bps, blocksize, samplerate;
	int res;

	blocksize_code = get_bits(&s->gb, 4);

	sample_rate_code = get_bits(&s->gb, 4);

	assignment = get_bits(&s->gb, 4); /* channel assignment */
	if (assignment < 8 && s->channels == assignment + 1)
		decorrelation = INDEPENDENT;
	else if (assignment >= 8 && assignment < 11 && s->channels == 2)
		decorrelation = LEFT_SIDE + assignment - 8;
	else
	{
		return -13;
	}

	sample_size_code = get_bits(&s->gb, 3);
	if(sample_size_code == 0)
		bps = s->bps;
	else if((sample_size_code != 3) && (sample_size_code != 7))
		bps = sample_size_table[sample_size_code];
	else
	{
		return -14;
	}

	if (get_bits1(&s->gb))
	{
		return -15;
	}

	/* Get the samplenumber of the first sample in this block */
	s->samplenumber = get_utf8(&s->gb);

	/* samplenumber actually contains the frame number for streams
	   with a constant block size - so we multiply by blocksize to
	   get the actual sample number */
	if (s->min_blocksize == s->max_blocksize) {
		s->samplenumber *= s->min_blocksize;
	}

#if 0
	if (/*((blocksize_code == 6) || (blocksize_code == 7)) &&*/
	    (s->min_blocksize != s->max_blocksize)) {
	} else {
	}
#endif

	if (blocksize_code == 0)
		blocksize = s->min_blocksize;
	else if (blocksize_code == 6)
		blocksize = get_bits(&s->gb, 8) + 1;
	else if (blocksize_code == 7)
		blocksize = get_bits(&s->gb, 16) + 1;
	else
		blocksize = blocksize_table[blocksize_code];

	if(blocksize > s->max_blocksize) {
		return -16;
	}

	if (sample_rate_code == 0) {
		samplerate = s->samplerate;
	} else if ((sample_rate_code > 3) && (sample_rate_code < 12))
		samplerate = sample_rate_table[sample_rate_code];
	else if (sample_rate_code == 12)
		samplerate = get_bits(&s->gb, 8) * 1000;
	else if (sample_rate_code == 13)
		samplerate = get_bits(&s->gb, 16);
	else if (sample_rate_code == 14)
		samplerate = get_bits(&s->gb, 16) * 10;
	else {
		return -17;
	}

	skip_bits(&s->gb, 8);
	crc8 = get_crc8(s->gb.buffer, get_bits_count(&s->gb) / 8);
	if(crc8) {
		return -18;
	}

	s->blocksize    = blocksize;
	s->samplerate   = samplerate;
	s->bps          = bps;
	s->decorrelation = decorrelation;

	// yield();
	/* subframes */
	if ((res = decode_subframe(s, 0, s->decoded0)) < 0)
		return res - 100;

	// yield();

	if (s->channels == 2) {
		if ((res = decode_subframe(s, 1, s->decoded1)) < 0)
			return res - 200;
	}

	// yield();
	align_get_bits(&s->gb);

	/* frame footer */
	skip_bits(&s->gb, 16); /* data crc */

	return 0;
}

/**
  * @brief  The application .
  * @retval void
  */
int flac_decode_frame(FLACContext *s, uint8_t *buf, int buf_size)
{
	int tmp;
	int i;
	int framesize;
	int scale;

	init_get_bits(&s->gb, buf, buf_size * 8);

	tmp = get_bits(&s->gb, 16);
	if ((tmp & 0xFFFE) != 0xFFF8) {
		return -41;
	}

	if ((framesize = decode_frame(s)) < 0) {
		s->bitstream_size = 0;
		s->bitstream_index = 0;
		return framesize;
	}

	// yield();

	scale = FLAC_OUTPUT_DEPTH - s->bps;
	switch(s->decorrelation)
	{
	case INDEPENDENT:
		if (s->channels == 1) {
			;
			for (i = 0; i < s->blocksize; i++)
			{
				s->decoded0[i] = s->decoded0[i] << scale;
			}
		} else {
			for (i = 0; i < s->blocksize; i++)
			{
				s->decoded0[i] = s->decoded0[i] << scale;
				s->decoded1[i] = s->decoded1[i] << scale;
			}
		}
		break;
	case LEFT_SIDE:
		//assert(s->channels == 2);
		for (i = 0; i < s->blocksize; i++)
		{
			s->decoded1[i] = (s->decoded0[i] - s->decoded1[i]) << scale;
			s->decoded0[i] = s->decoded0[i] << scale;
		}
		break;
	case RIGHT_SIDE:
		//assert(s->channels == 2);
		for (i = 0; i < s->blocksize; i++)
		{
			s->decoded0[i] = (s->decoded0[i] + s->decoded1[i]) << scale;
			s->decoded1[i] = s->decoded1[i] << scale;
		}
		break;
	case MID_SIDE:
		//assert(s->channels == 2);
		for (i = 0; i < s->blocksize; i++)
		{
			int mid, side;
			mid = s->decoded0[i];
			side = s->decoded1[i];

#if 1 //needs to be checked but IMHO it should be binary identical
			mid -= side >> 1;
			s->decoded0[i] = (mid + side) << scale;
			s->decoded1[i] = mid << scale;
#else

			mid <<= 1;
			if (side & 1)
				mid++;
			decoded0[i] = ((mid + side) >> 1) << scale;
			decoded1[i] = ((mid - side) >> 1) << scale;
#endif
		}
		break;
	}

	s->framesize = (get_bits_count(&s->gb) + 7) >> 3;

	return 0;
}

/**
  * @brief  The application .
  * @retval void
  */
int decode_frame_16(FLACContext *s, uint8_t *buf, int buf_size, int16_t *wavbuf)
{
	int tmp;
	int i;
	int framesize;
	int scale;

	int sampleCnt;
	
	int32_t * ch0;
	int32_t * ch1;
	
	ch0 = s->decoded0;
	ch1 = s->decoded1;
	
	init_get_bits(&s->gb, buf, buf_size * 8);

	tmp = get_bits(&s->gb, 16);
	if ((tmp & 0xFFFE) != 0xFFF8) {
		return -41;
	}

	if ((framesize = decode_frame(s)) < 0) {
		s->bitstream_size = 0;
		s->bitstream_index = 0;
		return framesize;
	}

	// yield();

	sampleCnt = s->blocksize;
	
	scale = FLAC_OUTPUT_DEPTH - s->bps;
	
	switch(s->decorrelation)
	{
		case INDEPENDENT :
			if (s->channels==1) 
			{
				do
				{
					*(wavbuf ++) = *ch0;
					*(wavbuf ++) = *(ch0 ++);
				}while(-- sampleCnt);
			}else 
			{
				do
				{
					*(wavbuf ++) = *(ch0 ++);
					*(wavbuf ++) = *(ch1 ++);
				}while(-- sampleCnt);
			}
			break;
		case LEFT_SIDE: 
			do
			{
				*(wavbuf ++) = *ch0;
				*(wavbuf ++) = *(ch0 ++) - *(ch1 ++);
			}while(-- sampleCnt);
			break;
		case RIGHT_SIDE: 
			do
			{
				*(wavbuf ++) = *(ch0 ++) + *ch1;
				*(wavbuf ++) = *(ch1 ++);
			}while(-- sampleCnt);
			break;
		case MID_SIDE: 
			do
			{
				int mid, side; 
				mid  = *(ch0 ++);
				side = *(ch1 ++);
				mid -= side>>1;   
				*(wavbuf ++) = (mid + side);
				*(wavbuf ++) = mid;
			}while(-- sampleCnt);
			break;
		default :
			do
			{
				*(wavbuf ++) = 0;
				*(wavbuf ++) = 0;
			}while(-- sampleCnt);
	} 

	s->framesize = (get_bits_count(&s->gb) + 7) >> 3;

	return 0;
}

// __attribute__ ((section ("RAMCODE")))
/**
  * @brief  The application .
  * @retval void
  */
int decode_frame_24(FLACContext *s, uint8_t *buf, int buf_size, int32_t *wavbuf)
{
	int tmp;
	int i;
	int framesize;
	int scale;

	int sampleCnt;
	
	int32_t * ch0;
	int32_t * ch1;
	
	ch0 = s->decoded0;
	ch1 = s->decoded1;
	
	init_get_bits(&s->gb, buf, buf_size * 8);

	tmp = get_bits(&s->gb, 16);
	if ((tmp & 0xFFFE) != 0xFFF8) {
		return -41;
	}

	if ((framesize = decode_frame(s)) < 0) {
		s->bitstream_size = 0;
		s->bitstream_index = 0;
		return framesize;
	}
	
	// yield();

	sampleCnt = s->blocksize;
	
	scale = FLAC_OUTPUT_DEPTH - s->bps;
	
	// printf("Decode ok blocksize : %d\r\n", sampleCnt);
	// printf("Decode ok decorrelation : %d\r\n", s->decorrelation);
	
	switch(s->decorrelation)
	{
		case INDEPENDENT :
			if (s->channels==1) 
			{
				do
				{
					// printf("Mono count ->%d\r\n", sampleCnt);
					*(wavbuf ++) = *ch0;
					*(wavbuf ++) = *(ch0 ++);
				}while(-- sampleCnt);
			}else 
			{
				do
				{
					// printf("Srereo count ->%d\r\n", sampleCnt);
					*(wavbuf ++) = *(ch0 ++);
					*(wavbuf ++) = *(ch1 ++);
					
				}while(-- sampleCnt);
			}
			break;
		case LEFT_SIDE: 
			do
			{
				*(wavbuf ++) = *ch0;
				*(wavbuf ++) = *(ch0 ++) - *(ch1 ++);
			}while(-- sampleCnt);
			break;
		case RIGHT_SIDE: 
			do
			{
				*(wavbuf ++) = *(ch0 ++) + *ch1;
				*(wavbuf ++) = *(ch1 ++);
			}while(-- sampleCnt);
			break;
		case MID_SIDE: 
			do
			{
				int mid, side; 
				mid  = *(ch0 ++);
				side = *(ch1 ++);
				mid -= side>>1;   
				*(wavbuf ++) = (mid + side);
				*(wavbuf ++) = mid;
			}while(-- sampleCnt);
			break;
		default :
			do
			{
				*(wavbuf ++) = 0;
				*(wavbuf ++) = 0;
			}while(-- sampleCnt);
	} 

	s->framesize = (get_bits_count(&s->gb) + 7) >> 3;
	// printf("framesize : %d\r\n", s->framesize);
	return 0;
}


// __attribute__ ((section ("RAMCODE")))
/**
  * @brief  The application .
  * @retval void
  */
int decode_frame_24_lite(FLACContext *s, uint8_t *buf, int buf_size)
{
	int tmp;
	int i;
	int framesize;
	int scale;

	int sampleCnt;
	int subCnt;

	int32_t *ch0;
	int32_t *ch1;
	int32_t *temp;

	ch0 = s->decoded0;
	ch1 = s->decoded1;

	temp = s->decode_tmp;

	init_get_bits(&s->gb, buf, buf_size * 8);

	tmp = get_bits(&s->gb, 16);
	if ((tmp & 0xFFFE) != 0xFFF8) {
		return -41;
	}

	if ((framesize = decode_frame(s)) < 0) {
		s->bitstream_size = 0;
		s->bitstream_index = 0;
		return framesize;
	}

	// yield();

	sampleCnt = s->blocksize;
	
	scale = FLAC_OUTPUT_DEPTH - s->bps;

	// printf("Decode ok blocksize : %d\r\n", sampleCnt);
	// printf("Decode ok decorrelation : %d\r\n", s->decorrelation);
	// printf("dec %d \r\n", s->decorrelation);

	switch(s->decorrelation) {
		
	case INDEPENDENT :
		/*****
		do
		{
			// printf("Srereo count ->%d\r\n", sampleCnt);
			*(wavbuf ++) = *(ch0 ++);
			*(wavbuf ++) = *(ch1 ++);

		}while(-- sampleCnt);
		*****/

		subCnt = sampleCnt / 2;
		do {
			subCnt--;

			temp[subCnt] = ch0[sampleCnt - subCnt - 1];

		} while(subCnt);

		tmp = sampleCnt - 1;
		subCnt = sampleCnt / 2;
		do {
			subCnt--;

			// temp[subCnt] =  ch0[sampleCnt - subCnt - 1];

			ch0[tmp--]   =  ch1[subCnt];

			ch0[tmp--]   =  ch0[subCnt];

		} while(subCnt);

		tmp = 0;
		subCnt = sampleCnt / 2;
		do {
			subCnt--;

			ch1[tmp++]  =  temp[subCnt];

			ch1[tmp++]  =  ch1[sampleCnt - subCnt - 1];

		} while(subCnt);

		break;
	case LEFT_SIDE:
		/*****
		do
		{
			*(wavbuf ++) = *ch0;
			*(wavbuf ++) = *(ch0 ++) - *(ch1 ++);
		}while(-- sampleCnt);
		*****/

		subCnt = sampleCnt / 2;
		do {
			subCnt--;

			temp[subCnt] = ch0[sampleCnt - subCnt - 1];

		} while(subCnt);

		tmp = sampleCnt - 1;
		subCnt = sampleCnt / 2;
		do {
			subCnt--;

			// temp[subCnt]  =  ch0[sampleCnt - subCnt - 1];

			ch0[tmp--]    =  ch0[subCnt] - ch1[subCnt];

			ch0[tmp--]    =  ch0[subCnt];

		} while(subCnt);

		tmp = 0;
		subCnt = sampleCnt / 2;

		do {
			subCnt--;

			ch1[tmp++]  =  temp[subCnt];

			ch1[tmp++]  =  temp[subCnt] - ch1[sampleCnt - subCnt - 1];

		} while(subCnt);

		break;
	case RIGHT_SIDE:
		/*****
		do
		{
			*(wavbuf ++) = *(ch0 ++) + *ch1;
			*(wavbuf ++) = *(ch1 ++);
		}while(-- sampleCnt);
		*****/

		subCnt = sampleCnt / 2;
		do {
			subCnt--;

			temp[subCnt] = ch0[sampleCnt - subCnt - 1];

		} while(subCnt);

		tmp = sampleCnt - 1;
		subCnt = sampleCnt / 2;
		do {
			subCnt--;

			// temp[subCnt]   =  ch0[sampleCnt - subCnt - 1];

			ch0[tmp--]     =  ch1[subCnt];

			ch0[tmp--]     =  ch0[subCnt] + ch1[subCnt];

		} while(subCnt);

		tmp = 0;
		subCnt = sampleCnt / 2;
		do {
			subCnt--;

			ch1[tmp++]  =  temp[subCnt] + ch1[sampleCnt - subCnt - 1];

			ch1[tmp++]  =  ch1[sampleCnt - subCnt - 1];

		} while(subCnt);

		break;
	case MID_SIDE:
		/*
		do
		{
			int mid, side;
			mid  = *(ch0 ++);
			side = *(ch1 ++);
			mid -= side>>1;
			*(wavbuf ++) = (mid + side);
			*(wavbuf ++) = mid;
		}while(-- sampleCnt);
		*/

		subCnt = sampleCnt / 2;
		do {
			subCnt--;

			temp[subCnt] = ch0[sampleCnt - subCnt - 1];

		} while(subCnt);

		tmp = sampleCnt - 1;
		subCnt = sampleCnt / 2;
		do {
			int mid, side;

			subCnt--;

			// temp[subCnt] = ch0[sampleCnt - subCnt - 1];

			mid  = ch0[subCnt];
			side = ch1[subCnt];
			mid -= side >> 1;

			ch0[tmp--]  =  mid;

			ch0[tmp--]  =  (mid + side);

		} while(subCnt);

		tmp = 0;
		subCnt = sampleCnt / 2;

		do {
			int mid, side;

			subCnt--;

			mid  = temp[subCnt];
			side = ch1[sampleCnt - subCnt - 1];
			mid -= side >> 1;

			ch1[tmp++]  =  (mid + side);

			ch1[tmp++]  =  mid;

		} while(subCnt);

		break;
	default :
		do {
			// *(wavbuf ++) = 0;
			// *(wavbuf ++) = 0;
			*ch0++ = 0;
			*ch1++ = 0;
			
		} while(-- sampleCnt);
	}

	s->framesize = (get_bits_count(&s->gb) + 7) >> 3;
	// printf("framesize : %d\r\n", s->framesize);
	return 0;
}



